Self-closing connectors are well known and are used in many applications, and in particular in those applications requiring a high degree of security, for example aeronautics, where they are used for the hydraulic controls of an aircraft and for verification thereof.
Such a connector is essentially constituted by a duct through a body, the duct being terminated by a seat-forming orifice, together with a sliding valve plate inside the duct and on which a pressure spring acts in such a manner as to hold the valve plate against the seat. In broad outline, a connector thus comprises a male portion and a female portion which are complementary to each other. When these two connector portions are not coupled to one another, they are closed by their respective valve plates. Under such conditions no fluid can escape from the ducts to which the connector portions are associated and, likewise, no gaseous, solid, or liquid impurities can enter the ducts.
When it is necessary to interconnect two ends, they are brought into end-to-end contact and pressed against each other, thereby, in a preliminary stage, opening a first one of the two valve plates to release fluid under pressure from the associated duct, which fluid, in a second stage, exerts pressure on the other valve plate and moves it in turn, thus opening the orifice with which the second valve plate is associated. The second valve orifice could alternatively be opened mechanically. Means are also provided for locking the two connectors portions together to prevent them from coming apart accidentally.
As a consequence from the above outline, it can be seen that the two valve plates in the two connector portions are displaced from their respective seats to provide fluid continuity between their ducts, and the two ducts are then interconnected with the above-mentioned advantages.
However, in some applications, such connectors have a considerable drawback. It may happen that connectors with given characteristics, as described above, are used in surroundings where the ambient pressure is high, and in particular where the ambient pressure may be high enough to exert an opening force on the face of a valve plate, in spite of the opposing forces exerted thereon by its return spring and by the fluid under pressure inside the duct. This applies, in particular, to self-closing connectors used underwater at depth.
Preferred embodiments of the present invention mitigate this drawback and provide a self-closing connector of the type having sliding valve plates, which connector is insensitive to the pressure of the ambient medium in which it is used.